A heat exchanger includes: a hollow heat recovery member having an inner peripheral surface and an outer peripheral surface in an axial direction, and an inflow end face and an outflow end face for a first fluid in a direction perpendicular to the axial direction; a first outer cylindrical member having an inflow port and an outflow port for the first fluid; a first inner cylindrical member having an inflow port and an outflow port for the first fluid, the first inner cylindrical member being fitted to the inner peripheral surface of the heat recovery member; and a second inner cylindrical member having an inflow port and an outflow port for the first fluid, the outflow port being located on an upstream side of the inflow end face of the heat recovery member based on the flow direction of the first fluid as a reference.